cicocicobum
Newbie level 4
Hello everybody,
I am working on a RF transmitter for space application compliant to DVB-S2 standard in terms of modulations and coding formats.
The output power has been defined considering compliance with ITU power flux density (PFD) on ground surface [dBW/m^2 over 4 kHz BW).
The performances are in line with the requirements for all MODCODs, but, it has been lately been discovered that for the dummy frames transmission (PLDUMMY, 90 Pi/2 BPSK modulated symbols followed by 36 x 90 symbol duration unmodulated carrier) the PFD cannot be respected, due to the peaks appearing the output spectrum, probably effect of the averaging over the two spectra of the modulated and unmodulated carrier.
I believe that being the PLDUMMY use part of the standard, this is recurring problem for any similar application.
Has anyone ever faced such a problem or any experience with temporarily short duration violation of ITU requirements?
Thanks in advance.
Regards
I am working on a RF transmitter for space application compliant to DVB-S2 standard in terms of modulations and coding formats.
The output power has been defined considering compliance with ITU power flux density (PFD) on ground surface [dBW/m^2 over 4 kHz BW).
The performances are in line with the requirements for all MODCODs, but, it has been lately been discovered that for the dummy frames transmission (PLDUMMY, 90 Pi/2 BPSK modulated symbols followed by 36 x 90 symbol duration unmodulated carrier) the PFD cannot be respected, due to the peaks appearing the output spectrum, probably effect of the averaging over the two spectra of the modulated and unmodulated carrier.
I believe that being the PLDUMMY use part of the standard, this is recurring problem for any similar application.
Has anyone ever faced such a problem or any experience with temporarily short duration violation of ITU requirements?
Thanks in advance.
Regards